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Title: Thermodynamic data of Ba{sub 0.6}Sr{sub 0.4}Co{sub 0.8}Fe{sub 0.2}O{sub 3−δ} SOFC cathode material

Graphical abstract: Partial molar energy of oxygen dissolution (ΔG{sup −}{sub O{sub 2}}) and equilibrium partial pressure of oxygen (log⁡p{sub O{sub 2}}) of perovskite material with the composition Ba{sub 0.6}Sr{sub 0.4}Co{sub 0.8}Fe{sub 0.2}O{sub 3−δ} as a function of temperature. - Highlights: • We report relevant data for thermodynamic stability of Ba{sub 0.6}Sr{sub 0.4}Co{sub 0.8}Fe{sub 0.2}O{sub 3−δ} perovskite compound. • Temperature of structural transformations related to the charge compensation of the material system is evidenced. • The results are discussed based on the properties-defect structure relationship. - Abstract: The compound Ba{sub 0.6}Sr{sub 0.4}Co{sub 0.8}Fe{sub 0.2}O{sub 3−δ} with perovskite structure has been studied focusing mainly on the thermodynamic stability in correlation to the change in the oxygen stoichiometry. The thermochemical behavior has been investigated from room temperature to 1300 K by thermal gravimetry and differential thermal analysis in air and by calorimetry in scanning mode in Argon. The temperature dependence of enthalpy (ΔH{sup T}{sub 298}) in the temperature range of 300–900 K was measured by drop calorimetry. Thermodynamic properties represented by the relative partial molar free energies, enthalpies and entropies of oxygen dissolution in the perovskite phase, as well as the equilibrium partial pressures of oxygen have been obtained in the temperature rangemore » of 823–1273 K using solid electrolyte electrochemical cells (EMF). The influence of the oxygen stoichiometry on the thermodynamic properties was examined using a coulometric titration technique coupled with EMF measurements. The results are discussed based on the strong correlation between the energetic parameters and the charge compensation of the material system.« less
Authors:
 [1] ;  [1] ; ; ; ;  [2] ; ;  [1] ;  [3] ; ;  [4]
  1. Institute of Physical Chemistry “Ilie Murgulescu”, Romanian Academy, Bucharest (Romania)
  2. Ivan Javakhishvili Tbilisi State University, R. Agladze Institute of Inorganic Chemistry and Electrochemistry, Tbilisi, Georgia (United States)
  3. Electron Microscopy ETH Zurich, ETH Zurich, Zurich (Switzerland)
  4. Nonmetallic Inorganic Materials, Department of Materials, ETH Zurich, Zurich (Switzerland)
Publication Date:
OSTI Identifier:
22420558
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Bulletin; Journal Volume: 57; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; BARIUM COMPOUNDS; CALORIMETRY; COBALT COMPOUNDS; DIFFERENTIAL THERMAL ANALYSIS; ELECTROCHEMISTRY; ELECTROMOTIVE FORCE; ENTHALPY; ENTROPY; FERRITES; FREE ENERGY; GRAVIMETRY; PARTIAL PRESSURE; PHASE TRANSFORMATIONS; SOLID ELECTROLYTES; SOLID OXIDE FUEL CELLS; STRONTIUM COMPOUNDS; TEMPERATURE DEPENDENCE; THERMAL GRAVIMETRIC ANALYSIS